木薯酒精废水高温厌氧消化系统中酶的提取与分布的研究

Studies on the Extraction and Distribution of the Enzymes in the Thermophilic Anaerobic Digestion System of Cassava-Ethanol Wastewater

木薯酒精废水中固形物(干基)的主要成分为纤维素和半纤维素,分别为30%和18%。由于内切-β-1,4-葡聚糖苷酶(CMC酶)和木聚糖酶在高温厌氧消化过程中对纤维素和半纤维素的水解起关键作用,作者比较了从厌氧污泥中提取CMC酶和木聚糖酶的6种方法,并分析了其在厌氧污泥中的分布情况。结果表明,用质量分数1% Triton X-100来提取CMC酶和木聚糖素酶是一种高效且温和的酶提取方法,且至少有占总酶质量90%的CMC酶和70%的木聚糖酶分布在污泥絮凝体(细胞表面或胞外聚合物)中。

The main components of the solid content in the cassava-ethanol wastewater were cellulose and hemicellulose, which account for about 300% and 18%, respectively. Because the endo-l^-l, 4-glucanase （CMCase） and xylanase played a key role in hydrolyzing cellulose and hemicellulose during the thermophilic anaerobic digestion process, six methods for extracting CMCase and xylanase from the anaerobic sludge were compared and the distribution of these enzymes in the sludge was also investigated in this study. The results demonstrated the extraction of CMCase and xylanase using 1% Triton X-100 was an efficient and gentle method, meanwhile, at least 90% of CMCase and 700% of xylanase were immobilized on the flocs （the surface of cells or the extracellular polymeric substances）.